Safety switch



June 18, 1957 w. o. WALKUP 2,796,479

SAFETY swma Filed Nov. 19, 1954 2 Sheets-Sheet 1 INVENTOR. 5 W/LL A M 0.W44 za June 18, 1957 w. o. WALKUP 2,796,479

SAFETY SWITCH Filed Nov. 19, 1954. 2 Shets-Sheet 2 a I I L 1 0 1 Z 27 V-k? [I 1 /Z 38 E i /3 IN V EN TOR.

WILL /AM 0. 14/4 601? United States, Patent SAFETY SWITCH William O.Walkup, Meadow Bridge, W. Va. Application November 19, 1954, Serial No.470,061

1 Claim. (Cl. ZOO-61.5)

This invention relates to' automatic safety switches, and moreparticularly to an improved automatic switch for use on a motor vehicleto open the ignition circuit or other electrical circuits of thevehicle.

A main object of the invention is to provide a novel and improvedautomatic circuit breaker arranged to open an electrical circuit in theevent of a sudden jar or collision, or by manual control, if desired,the improved circuit breaker being simple in construction, involvingvery few parts, and being reliable in operation.

A further object of the invention is to provide an improved automaticsafety switch suitable for use in automotive vehicles, aircraft, or thelike, the automatic switch being arranged to open responsive to a suddenjar, collision or other unsual impact, and being also arranged so thatit may be manually controlled, the improved circuit breaker involvinginexpensive components, being rugged in construction, being reliable inoperation, and being arranged to render the electrical circuits of thevehicle or aircraft in which the device is employed inoperative as aprecaution against fire or theft, or under emergency conditions such asin the event of collision or the like.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

Figure 1 is a vertical cross sectional view taken through a verticalwall of a vehicle equipped with an improved automatic circuit breakerconstructed in accordance with the present invention.

Figure 2 is a vertical cross sectional view taken on the line 2-2 ofFigure 1.

Figure 3 is a top view of the circuit breaker of Figures 1 and 2.

Figure 4 is a vertical cross sectional view taken through the circuitbreaker on the line 4-4 of Figure 3, showing the contacts thereof open.

Figure 5 is a vertical cross sectional view taken on the line 55 ofFigure 3.

Figure 6 is a horizontal cross sectional view taken on the line 6-6 ofFigure 1.

Figure 7 is a horizontal cross sectional view taken on the line 77 ofFigure 2.

Referring to the drawings, the improved circuit breaker is designatedgenerally at 11 and comprises a supporting frame having the parallelvertical members 12 and 13, the vertical member 12 being adapted to besecured to a suitable vertical portion of a vehicle, for example, to aselected portion of the fire wall of a motor vehicle, for example, aportion of the fire wall 14 thereof. The lower portion of the verticalmember 12 is rigidly connected to the lower portion of the verticalmember 13 by a disc member 15, and the top portions of the members 12and 13 are rigidly connected by a pair of parallel plate members 16 and17 secured to opposite sides of the members 12 and 13 and extendinghorizontally, as shown in Figures 1 and 3. Rigidly connecting "ice theintermediate portions of the members 12 and 13 is a disc member 18 whichis formed on its bottom surface with the central circular recess 19.

Designated at 20 is a contact plunger which is slidably disposed througha central aperture 21 in the disc member 18. The upper portion of theplunger 20 extends slidably through a central aperture 22 formed in ahorizontally positioned bar member 23 rigidly secured at its ends to thevertical bar members 12 and 13 above and parallel to the member 18. Thebar member 23 is of conducting material and is provided with a terminalstud 24, said terminal stud being connected by a flexible wire 25 to thetop end of the contact plunger 20.

A coiled spring 26 surrounds the contact plunger 20 and bears betweenthe member 23 and the transverse pin 27 extending through the lowerportion of the contact plunger 20, biasing the contact plunger 20downwardly. Secured to the top end of the contact plunger 20 is aflexible cable 28 which extends over a pulley 29 journaled on a shaft 30secured between the rn'embers 16 and 17, the cable 28 extending throughan aperture 31 in the fire wall 14 to the dashboard of the vehicle whereit is provided, with a suitable manual operating knob, not shown.

It will be understood that by applying tension to the cable 28, as bypulling on its operating knob, the plunger member 20 may be raised, whendesired, to cause the switch to be manually opened, .as will bepresently explained.

Slidably engaged through diametrically opposite vertical apertures 32,32 in the member 18 are the respec tive vertical rods 33, 33 which arerigidly connected at their top ends by -a horizontal bar 34 and whichare rigidly connected at their bottom, ends by an annular disc member35. The member 34 extends transversely over the bar member 23 and isformed with a central aperture 36 through which the cable 28 extends, asshown in Figure 4. v

The annular disc is formed with a relatively large central aperture 37through which extends the shank portion 38 of an upstanding contactelement, said contact element being formed at its bottom end with aspherical recess 39 which receives the spherical head 40 of a terminalstud 41 centrally secured in the bottom disc member 15. Thus, the shankmember 38 is pivotally mounted on the spherical head 40 for universalpivoting thereon in the aperture 37 of the annular ring 35. The annularring 35 is preferably made of suitable insulating material, as is themember 18 through which the plunger 20 extends.

The top end of the shank 38 is integrally formed with an upwardlyflaring conical head 42 of substantial weight, and is further formedwith the top contact stud 43 which is received in and is movable in therecess 19, and which may be engaged with the bottom end of the plunger20 in the manner shown in Figure 2. The force of the spring 26 issufficient so that when the stud 43 is centered and is engaged by thebottom end of the plunger 20, stud 43 will be held in engagement withthe bottom end of the plunger 20 by frictional force and will not bedislodged therefrom except in the event of a collision or other severeimpact. Under these conditions, the weight of the head 42 will cause theshank 38 to pivot laterally and to disengage the stud 43 from the bottomend of the plunger 20, causing the stud 43 to swing laterally againstthe side wall of the recess 19, to a position such as that shown inFigure 4, electrically disconnecting the terminal stud 41 from theterminal stud 24.

Secured to the intermediate portion of the top bar 34 is a 'flexiblecable 45 which passes over a pulley 46 rotatably mounted on thetransverse pin 30, the cable 45 passing through the aperture 31 to thedashboard of the vehicle where it is provided with a suitable manualoperating knob, not shown. By exerting tension on the cable 45, and bypulling its operating knob, the frame comprising the members 33 andtheir top and bottom connecting elements '34 and 35 may be elevated,whereby the central aperture 37 of the annular member 35 camminglyengages the conical head 42 and rotates said conical head from itslaterally swung position, such as that shown in Figure 4, to itscentered position, such as that shown in Figure 2, the carnming actionbeing sufiicient .to cause the stud 43 to be engaged beneath the bottomend of'the plunger 20, whereby the switch may be reset to its normalclosed position.

Upon release of the cable 45, the frame above described descends to itsnormal position, either by its own weight, or by the provision of asuitable spring, acting to bias the frame downwardly, not shown.

As above explained, the plunger 20 may be elevated by exerting a manualpull on the flexible cable 28, in which case, the lower end of theplunger disengages from the stud 43, allowing the shank 38 to rotatelaterally to the position of Figure 4, thus opening the electricalconnection between terminal studs 41 and 24. To reclose said electricalconnection, the cable 45 is elevated by means of its operating knob torestore the shank 38 to its centered position, shown in Figure 2, and tocause the stud 43 to be again engaged beneath the bottom end ofthe'plunger 20. Thus, the operator of the vehicle may manually open thecircuit controlled by the switch by allowing the stud 43 to disengagefrom plunger 20 in the manner above described, namely, by pulling on thecable 28 by employing its manual operating knob. The circuit can bereclosed by pulling on the cable 45, as above described, when desired.

It will be understood that the switch above described,

While a specific embodiment of an improved safety switch for vehicles orthe like has been disclosed in the foregoing description, it will beunderstood that various modifications within the spirit of the inventionmay occur to those skilled in the art. Therefore, it is intended that nolimitations be placed on the invention except as defined by the scope ofthe appended claim.

What is claimed is: I

In a circuit breaker of the character described, a support, a platemember rigidly secured to said support, a contact plunger slidablyengaged through said plate member and guided for sliding movement normalto said plate member, a movable rod-like contact element opposite saidcontact plunger, a terminal stud in the bottom portion of said supporthaving a spherical head, said contact element being formed with aspherical recess in its bottom end receiving and being rotatably engagedon said head, the top end of said contact element being engageable bythe end of the contact plunger, a coiled spring arranged axially withrespect to and acting axially on said contact plunger and biasing saidcontact plunger toward said contact element and exerting sufiicientforce on the plunger to cause the end of the plunger to be :frictionally engaged with the end of the contact element, said contaetelement being swingable laterally out of engagement with said plunger, amovable restoring member carried by said suppoit, said restoring memberhaving an aperture through which the rod-like contact element extendsand which is arranged to center said contact element for engagement bythe end of the plunger responsive to the movement of said restoringmember, frame means secured to said restoring member and having a.portion thereof extending slid-- ably through said plate member parallelto said plunger, whereby said restoring member is guided for movementalong a path parallel to the axis of said plunger, and respectiveflexible control-cables connected to said frame means. and said plunger.

References Cited in the file of this patent UNITED STATES PATENTS1,868,365 Paul July 19, 1932 2,188,144 Eytman Jan. 23, 1940 2,190,934Courtney Feb. 20, 1940

